Change ASP.Net GridView row backgroud color based on condition using C#

 hi kankon,

Please refer below code.

HTML

<asp:GridView runat="server" ID="gvEmployees" AutoGenerateColumns="false" DataKeyNames="EmployeeId,CountryId"
    OnRowDataBound="OnRowDataBound">
    <Columns>
        <asp:BoundField  HeaderText="Employee ID" DataField="EmployeeId" />
        <asp:BoundField HeaderText="Employee Name" DataField="EmployeeName" />
        <asp:TemplateField HeaderText="Cancel request">
            <ItemTemplate>
                <asp:Button ID="btnNewRequest1" runat="server" Text="Cancel request" OnClick="Oncancel" ></asp:Button>
            </ItemTemplate>
            <ItemStyle HorizontalAlign="Center" />
        </asp:TemplateField>
        <asp:CommandField ButtonType="Link" ShowDeleteButton="true" HeaderText="حذف"
            ControlStyle-Width="50" HeaderStyle-HorizontalAlign="Center" HeaderStyle-Width="50">
            <ControlStyle Width="50px"></ControlStyle>
            <HeaderStyle HorizontalAlign="Center" Width="50px"></HeaderStyle>
        </asp:CommandField>
    </Columns>
</asp:GridView>

Namespaces

using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Drawing;

Code

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}

private void BindGrid()
{
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(conString))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT EmployeeId, EmployeeName, CountryId FROM Employees", con))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                sda.SelectCommand = cmd;
                using (DataTable dt = new DataTable())
                {
                    sda.Fill(dt);
                    gvEmployees.DataSource = dt;
                    gvEmployees.DataBind();
                }
            }
        }
    }
}

protected void Oncancel(object sender, EventArgs e)
{
    GridViewRow row = (sender as Button).NamingContainer as GridViewRow;
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(conString))
    {
        using (SqlCommand cmd = new SqlCommand("UPDATE EMPLOYEES SET CountryId= @CountryId WHERE EmployeeId=@id", con))
        {
            string id = gvEmployees.DataKeys[row.RowIndex].Values[0].ToString();
            cmd.Parameters.AddWithValue("@CountryId", "Cancelled");
            cmd.Parameters.AddWithValue("@id", id);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }

    this.BindGrid();
}

protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        if (gvEmployees.DataKeys[e.Row.RowIndex].Values[1].ToString() == "Cancelled")
        {
            e.Row.BackColor = Color.Red;
        }
    }
}

Screenshot